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Fluorescence Yield Xanes and Exafs Experiments: Application to Highly Dilute and Surface Samples

Published online by Cambridge University Press:  06 March 2019

Glenn A. Waychunas
Affiliation:
Center for Materials Research
Gordon E. Brown Jr.
Affiliation:
Department of Geological and Environmental Sciences and Stanford Synchrotron Radiation Laboratory Stanford University, Stanford CA 94305
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Extract

The development of intense synchrotron radiation sources during the last twenty years has enabled several types of x-ray spectroscopy and scattering techniques to come into practical use. One of the most significant methods for the characterization of extremely dilute samples is high resolution x-ray absorption-edge spectroscopy. The technique is usually divided into two separate methods according to whether the x-ray absorption near edge structure (XANES) or the extended x-ray absorption fine structure (EXAFS) is analyzed. XANES features are due mainly to bound-state electronic transitions just below, and on the low energy side of the edge, and to multiple scattering resonances on the top of the edge and at somewhat higher energies. EXAFS features are oscillations due to ejected photoelectron back scattering interference processes in the close vicinity of the absorber atom. XANES analysis is used to determine atom valence, atom site distortion from regular geometries, and other details of the atom site. EXAFS features can be analyzed to recover interatomic distances between the absorber atom and its first few shells of neighbors, as well as the number and types of these neighbors. Together these techniques can provide an atomspecific probe of die short-range structure within almost any type of condensed matter.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1993

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References

Abruna, H.D., 1991,“Electrochemical Interfaces: Modem Techniques for In-situ Interface Characterization,” VCH Publishers, New York.Google Scholar
Bargar, J.R., Cheah, S.-F., O'Pay, P.A., Papelis, C.J., Persson, P., Thompson, H.A., Towle, S.N., Xu, N., Pickering, I.J., Paries, G.A. and Brown, G.E. Jr., 1993, X-ray absorption spectroscopy of ion sorption complexes at solid-water interfaces, 1992 Activity Report Stanford Synchrotron Radiation Laboratory, SSRL-1992: 69.Google Scholar
Cramer, S.P. and Scott, R.A., 1981, New fluorescence detection system for x-ray absorption spectroscopy, Rev. Sci. Instr. 52:395.Google Scholar
Cramer, S.P., Tench, O., Yocum, M. and George, G.N., 1988, A 13-element Ge detector for fluorescence EXAFS, Nucl. Inst. Methods A266: 586.Google Scholar
Furenlid, L.R., Kraner, H.W., Rogers, L.C., Cramer, Stephani, S.P., Beuttenmuller, D., R.H. and Beren, J., 1992, The NSLS 100 element solid state array detector, Nucl. Inst. Methods A319: 408.Google Scholar
Hastings, J.B., Eisenberger, P., Lengeler, B. and Perlman, M.L., 1979, Local-structure determination at high dilution: Internal oxidation of 75-ppm Fe in Cu, Phys. Rev. Lett. 43: 1807.Google Scholar
Heald, S.M., Chen, H. and Tranquada, J.M., 1988, Glancing-angle extended x-rayabsorption fine structure and reflectivity studies of interfacial regions, Phys. Rev. B38: 1016.Google Scholar
Kirkland, J.P., Jach, T., Neiser, R.A. and Bouldin, C.E., 1988, PIN diode detectors for synchrotron x-rays, Nucl, Inst. Methods A266: 602.Google Scholar
Stern, E.A and Heald, S.M., 1979,X-ray filter assembly for fluorescence measurements of x-ray absorption fine structure, Rev. Sci. Instr. 50: 1579.Google Scholar
Warburton, W.K., 1986, Filtered energy dispersive detector (EDD) arrays: superior detectors of EXAFS from very diluted solutions, Nucl. Inst Methods A246: 541.Google Scholar